@jojoguy10 Include @jojoguy10 in your post and this person will be notified via email.

Hello all,

I have a machine that is used to measure the thickness of flat pieces across the width and length. There are 5 thickness gages across the width (set up by an operator for the different widths of parts), and the system automatically collects a thickness data point, for each gage, every 6 inches down the length of the part.

We want to look at the accuracy and repeatability of this system.

My question is, should I perform a Gage R&R for each thickness sensor? Also, since I need a single data point to compare against, should I use an average of the collected data points, or should I use a common data point from piece-to-piece (e.g. 12 inches from the first edge for every part).

@jojoguy10 Include @jojoguy10 in your post and this person will be notified via email.

Thanks, guys!

Follow-up question: If I wanted to do a gage R&R for each sensor, how should I compare part-to-part? Should I average the thickness data points from the sensor and use that to compare between parts (for part variability)?

@jazzchuck Include @jazzchuck in your post and this person will be notified via email.

I recommend choosing a common data point along the length. If you use an average, your study will underestimate the part to part variation, since the variance of sample averages is always less than the variance of individual measurements.